<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="app">
    <h2>{{message}}</h2>
    <h2 v-once>{{message}}</h2>

</div>
<script src="../js/vue.js"></script>
<script>
    const app = new Vue({
        el: "#app",
        data: {
            message: "hello"
        }
    })
</script>
</body>
</html>